Abstract
The objective of this paper is a comparison of viscoelastic properties of Kelvin-Voigt microbeams described by integer and fractional derivative. The comparison is made for an initially stressed viscoelastic microbeam subjected to an ultra-fast laser heat source. Moreover, the analytical solutions for deflection and the temperature are evaluated using the Laplace transform technique. The dynamic viscoelastic of the responses of the microbeam are numerically calculated and investigated graphically. Numerical discussions show that an increase in fractional order derivative causes a decrease in behavior amplitudes of the microbeam.